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The Spondyloarthritis Research and Therapy Network (SPARTAN), founded in 2003 to promote research, education, and treatment of ankylosing spondylitis (AS) and related forms of spondyloarthritis (SpA), held its 7th Annual Research and Education Meeting in July 2009 in Houston, Texas. Current controversies in SpA discussed during the meeting included an update on the epidemiology of AS, axial SpA, and inflammatory back pain; the adequacy of the mSASS to assess radiographic involvement; the helpfulness of magnetic resonance imaging in assessing disease progression; the reliability of metrology in assessing damage; and whether biologic agents alter the course of AS. Presentations also were made on psoriasis in the SCID mouse model; the challenges and opportunities of SpA in China; a discussion of the special needs in managing SpA in Ibero-America, and the SPARK Survey in Europe and North America.

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OBJECTIVE: To assess the discriminative ability and correlation of the Ankylosing Spondylitis Disease Activity Score (ASDAS) and Bath Ankylosing Spondylitis Activity Disease Activity Index (BASDAI) with disease activity in axial psoriatic arthritis (AxPsA). METHODS: Patients with AxPsA were selected from a large prospective cohort study of psoriatic arthritis. Patient and physician global scores were used as constructs of disease activity. Patients were categorised into high and low disease activity states based on patient and physician global assessment scores and physician's decision to change treatment. Statistical analysis included descriptive statistics, linear and logistic regression. RESULTS: 201 patients with AxPsA were included in the study. ASDAS and BASDAI showed good correlation with disease activity as reflected by the patient global score (correlation coefficients (r) for BASDAI 0.84, ASDAS-B 0.77, ASDAS-C 0.81, p < 0.001) and the physician global score (r = 0.53 for BASDAI, r = 0.50 for ASDAS-B, r = 0.55 for ASDAS-C, p < 0.001). Both scores showed good discriminative ability between high and low disease activity states. However, there were no significant differences between areas under the curve for the models that compared ASDAS with BASDAI for each definition of disease activity state. CONCLUSIONS: In patients with AxPsA, ASDAS and BASDAI scores show similar good to moderate discriminative ability and correlation with different constructs of disease activity. ASDAS was not superior to BASDAI in its ability to discriminate between high and low disease activity states in AxPsA.

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OBJECTIVE: To determine the association between folate pathway gene polymorphisms and the effectiveness, toxicity, and drug survival of methotrexate (MTX) in psoriatic arthritis (PsA). METHODS: Data were obtained from a longitudinal cohort of PsA patients evaluated according to a standard protocol. Data on duration of drug therapy, dose, side effects, and reasons for discontinuation are systematically recorded. Patients treated with MTX after clinic admission who had > or = 3 swollen joints prior to initiating MTX therapy were selected for evaluation of effectiveness. Response to MTX treatment was assessed at 6 months. Data from all patients treated in the clinic with MTX were used in evaluation of toxicity and drug survival. The following single-nucleotide polymorphisms (SNP) were measured using the Sequenom platform: MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), DHFR -473T>C (rs1650697), DHFR 35289A>G (rs1232027), and RFC 80G>A (rs1051266). Fisher's exact test, logistic regression, and Cox proportional hazard analyses were used to determine association. RESULTS: Two hundred eighty-one patients were identified from the database. All patients were included in the analysis for side effects and drug survival, and 119 patients were included in the effectiveness analysis. The minor A allele of DHFR gene at +35289 was the only SNP demonstrating association with response to MTX therapy (OR 2.99, p = 0.02). Patients homozygous for the minor allele of MTHFR 677C/T (677TT) had more liver toxicity (Fisher exact test, p = 0.04). CONCLUSION: Polymorphisms of the DHFR gene may be associated with MTX efficacy. MTHFR 677TT may have a relationship with MTX-induced liver toxicity in PsA.

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OBJECTIVES: To assess the effectiveness of IA corticosteroid (IAS) injections in PsA and to determine the association between macrophage migration inhibition factor (MIF) gene polymorphism and response to IAS injections. METHODS: A cohort analysis of PsA patients who were followed prospectively was performed. Clinical response was defined as no tenderness or effusion in the injected joint at 3 months. Relapse was defined as re-occurrence of joint pain or effusion. MIF 173C > G genotyping (rs755622) was performed. RESULTS: Two hundred and twenty patients with 245 IAS injections were included in the study. The probability of responding at 3 months was 41.6%. Within 12 months, 25.5% of the joints relapsed. Clinical factors that were associated with response included duration of psoriasis [Odds ratio (OR) 1.03] and the use of MTX or anti-TNF agents at the time of injection (OR 2.68). Factors that were associated with relapse included injection into large joints (OR 4.58) and elevated sedimentation rate (OR 15.0), whereas absence of clinical and/or radiographic damage (OR 0.23) and duration of PsA (OR 0.92) reduced risk of relapse. MIF polymorphism was not associated with clinical response, but was associated with relapse (OR 3.2). On multivariate analysis including clinical covariates, the association between MIF polymorphism and relapse was lost. CONCLUSIONS: IAS injections are effective in PsA. MIF gene polymorphism is associated with relapse. However, this effect is explained by clinical variables that reflect disease activity, suggesting that MIF gene polymorphism influences inflammatory activity.

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OBJECTIVE: To determine predictors and time to response to treatment with TNF-alpha blockers in patients with PsA in a longitudinal observational cohort. METHODS: We performed a cohort analysis of patients who were followed prospectively in a large PsA clinic. Response to treatment was defined as an improvement of at least 40% in active (tender and/or swollen) and swollen joint count (SJC) and 50% improvement in the Psoriasis Area and Severity Index (PASI) score. RESULTS: Ninety-five patients were included in the analysis. Of the total patients, 72.6 and 77.9% demonstrated 40% improvement in active joint counts at 3 and 12 months, respectively. Also, 80.5 and 87.4% of the patients showed 40% improvement in SJC at 3 and 12 months, respectively. A PASI50 was achieved by 54 and 60.4% after 3 and 12 months of treatment, respectively. Of 17 patients who did not achieve 40% improvement in total SJC at 3 months, 11 (64.7%) responded at 12 months. In multivariate analysis, the number of swollen joints at baseline predicted response of total active joints at 12 months [odds ratio (OR) 1.34; P = 0.02], whereas past use of TNF-alpha blocker decreased odds of response (OR 0.05; P = 0.01). CONCLUSION: TNF-alpha blockers are effective in most PsA patients with the majority responding within 3 months of treatment. A significant proportion of the early non-responders will have a delayed response to treatment. Higher SJC at baseline and no prior use of TNF-alpha blockers predict response.

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OBJECTIVE: Axial involvement is an important manifestation of psoriatic arthritis (PsA). We aimed to identify risk factors associated with the presence of axial PsA (AxPsA) in patients with PsA. METHODS: Patients with AxPsA (bilateral sacroiliitis >or= grade 2/unilateral sacroiliitis >or= 3 and inflammatory neck/back pain or limited spinal mobility) at first clinic visit were identified from the University of Toronto PsA clinic database. Risk factors associated with the presence of AxPsA were determined. Subsequently, patients without AxPsA at first clinic visit were identified. Under a multistate framework, the proportion of patients with PsA who subsequently developed AxPsA was estimated robustly using marginal methods and a Markov model. Risk factors at baseline that were associated with future development of AxPsA were identified through multiplicative time-homogeneous Markov models. RESULTS: Our study included 206 patients. Fifty patients had AxPsA at first clinic visit. HLA-B*27, radiographic damage to peripheral joints, and elevated erythrocyte sedimentation rate (ESR) increased odds of having AxPsA, while family history of PsA decreased the odds. One hundred fifty-six patients did not have AxPsA at first clinic visit. On followup, 28 developed AxPsA, and 11 died. We estimated that after 10 years of followup, 15% would develop AxPsA. Nail dystrophy, number of radiographically damaged joints, periostitis, and elevated ESR increased the risk of developing AxPsA, while swollen joints decreased the risk. CONCLUSION: These results suggest that severe peripheral arthritis and HLA-B*27 are risk factors for AxPsA.

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Biomarkers may be used to screen patients with psoriasis for psoriatic arthritis (PsA) and to assess disease activity and severity. Candidate biomarkers should fulfil the key features of the OMERACT (Outcome Measures in Rheumatology) filter, that is, truth, discrimination, and feasibility. A number of biomarkers are currently being investigated in psoriatic disease for important clinical outcomes. Serum high sensitivity C-reactive protein, cartilage oligomeric matrix protein, interleukin 6 (IL-6), osteoprotegerin, matrix metalloprotease-3 (MMP-3), and the ratio of C-propeptide of type II collagen (CPII) to collagen fragment neoepitopes Col2-3/4 (long mono) (C2C) show promise as serum biomarkers that distinguish subjects with PsA from those with psoriasis alone. Serum MMP-3 and melanoma inhibitory activity, synovial fluid IL-1, IL-1 receptor-α, IL-6, IL-8, and chemokine CCL3 and synovial tissue CD3-positive T cells may prove useful as biomarkers of PsA activity. Circulating osteoclast precursors, Dickkopf-1, macrophage colony stimulating factor, receptor activator of nuclear factor-κB ligand, and bone alkaline phosphatase are strong candidates as biomarkers of radiographic change. Prospective studies to identify biomarkers for psoriatic disease are high on the research agenda of the Group for Research and Assessment of Psoriasis and PsA.